The geomagnetic field was quiet on February 7. Solar wind speed at SOHO ranged between 445 and 540 km/sec. The high latitude magnetometer at Andenes recorded very quiet levels. The above 10 MeV proton flux was at background levels at the end of the day.
Solar flux density measured at 20h UT on 2.8 GHz was 188.4 - decreasing 4.1 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 157.34. In comparison SC24 peaked on June 28, 2014 at 145.50. Current SC25 peak: 158.71 on June 27, 2023). The Potsdam WDC planetary A index was 4 (STAR Ap - based on the mean of three hour interval ap indices: 3.9). Three hour interval K indices: 01121111 (planetary), 00112321 (Boulder), 01100001 (Andenes).
The background x-ray flux is at the class C1 level (GOES 16).
At the time of counting spots (see image time), spots were observed in 14 active regions using 2K resolution (SN: 317) and in 13 active regions using 1K resolution (SN: 230) SDO/HMI images.
Region 13567 [N20W40] was quiet and stable.
Region 13570 [S02W32] was quiet and stable.
Region 13571 [S17W16] decayed slowly and
quietly.
Region 13572 [S12W61] decayed slowly and quietly.
Region 13574 [N17W05] was mostly quiet and stable. The region has reversed
polarities.
Region 13575 [S37W84] was mostly quiet after the major flare early in
the day.
Region 13576 [S15E29] still has magnetic delta structures in the
complex and spot rich leading spot section, a major flare is possible. C1
flares: C1.9 @ 01:13, C1.7 @ 22:54, C1.6 @ 23:19 UT
Region 13577 [N24W03] was quiet and stable.
Region 13578 [S04E41] decayed slowly and was mostly quiet. The region has reversed polarities.
C1 flares: C1.7 @ 00:36 UT
Spotted regions not observed (or interpreted
differently) by SWPC/USAF:
S9401 [S20W02] was quiet and stable.
S9404 [S14W74] decayed slowly and quietly.
S9407 [S16W57] was quiet and stable.
S9408 [S10E48] was mostly quiet and stable.
New region S9409 [S21E83] rotated into view with a mature spot.
C2+ flares:
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C2.5 | 00:05 | 13575 | GOES16 | ||
| C2.1 | 01:07 | 13575 | GOES16 | ||
| C2.5 | 01:24 | 13575 | GOES16 | ||
| C4.5 | 02:02 | 13575 | GOES16 | ||
| C4.0 | 02:12 | 13575 | GOES16 | ||
| C8.2 | 02:31 | 13575 | GOES16 | ||
| C4.5 | 02:56 | 13575 | GOES16 | ||
| M5.1 | 03:31 | S38W74 | 13575 | GOES16 | CME, LDE |
| C5.7 | 05:58 | S9408 | GOES16 | ||
| C3.1 | 07:22 | GOES16 | |||
| C2.3 | 08:39 | 13575 | GOES16 | ||
| C2.2 | 08:56 | 13576 | GOES16 | ||
| C2.3 | 09:32 | 13576 | GOES16 | ||
| C2.8 | 10:43 | 13576 | GOES16 | ||
| C3.0 | 10:48 | 13576 | GOES16 | ||
| C2.1 | 13:00 | 13576 | GOES16 | ||
| C4.9 | 13:41 | 13576 | GOES16 | ||
| C2.3 | 15:04 | 13576 | GOES16 | ||
| C2.3 | 15:33 | 13574 | GOES16 | ||
| C2.1 | 15:58 | 13574 | GOES16 | ||
| C2.0 | 16:35 | 13576 | GOES16 | ||
| C2.2 | 16:59 | 13574 | GOES16 | ||
| M1.3 | 18:06 | 13576 | GOES16 | LDE | |
| M1.2 | 18:19 | 13576 | GOES16 | ||
| C4.9 | 19:02 | 13575 | GOES16 | ||
| C2.0 | 19:50 | 13576 | GOES16 | ||
| C3.4 | 20:25 | 13576 | GOES16 | ||
| C2.0 | 21:37 | 13574 | GOES16 | ||
| C2.2 | 21:58 | S9406 | GOES16 | ||
| C2.1 | 22:13 | 13576 | GOES16 |
February 5, 7: No obviously Earth directed CMEs were observed.
February 6: A partial halo CME was observed after an M2.2 flare and a long duration M4.2 event peaking at 03:11 UT in AR 13575. A shock wave affected the corona far
away from the source. A
partial halo CME was associated with this event. The CME was visible in
LASCO C2 imagery from 02:36 UT. While the bulk of the CME is not headed for
Earth, there is a chance of a weak solar wind shock on February 9. A
nearly symmetrical full halo CME was observed near noon. While there was a
large filament eruption in the northern hemisphere that was suspected as the
origin, any CME associated with that event would be unlikely to cause a CME
with the observed mass distribution and intensity. The source of the CME is
thus likely to have been backsided.
[Coronal hole history (since October 2002)]
[Compare today's report to the situation one solar rotation ago:
28 days ago
27 days ago
26 days ago]
No obvious coronal holes are currently in or near Earth facing positions.
Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over upper middle and high latitudes is fair. Propagation on long distance northeast-southwest paths is poor.
The geomagnetic field is expected to be quiet on February 8. On February 9 there is a chance of weak CME effects associated with long duration events in AR 13575 early on February 6. Quiet to unsettled conditions are likely on February 9-10.
| Coronal holes (1) | Coronal mass ejections (2) | M and X class flares (3) |
1) Effects from a coronal hole
could reach Earth within the next 5 days. When the high speed
stream has arrived the color changes to green.
2) Effects from a CME are likely to be observed at Earth within 96 hours.
3) There is a possibility of either M or X class flares within the next 48 hours.
Green: 0-30% probability, Yellow: 30-70% probability, Red: 70-100% probability.
(Click on image for 2K resolution).
4K resolution.
Compare to the previous
day's image. 0.5K image
When available the active region map has a coronal hole polarity overlay where red (pink) is negative and blue is positive.
Data for all officially numbered solar regions according to the Solar Region Summary provided by NOAA/SWPC, all other regions are numbered sequentially as they emerge using the STAR spot number. Comments are my own, as is the STAR spot count (spots observed at or inside a few hours before midnight) and data for regions not numbered by SWPC or where SWPC has observed no spots. SWPC active region numbers in the table below and in the active region map above are the historic SWPC/USAF numbers. SWPC data considered to be not sufficiently precise (location, area, classification) are colored red.
| Active region | SWPC date numbered STAR detected |
Spot count | Location at midnight | Area | Classification | SDO / HMI 4K continuum image with magnetic polarity overlays |
Comment | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| SWPC/ USAF |
Magnetic (SDO) |
SWPC | STAR | Current | Previous | ||||||
| 2K | 1K | ||||||||||
| 13565 | 2024.01.27 2024.01.28 |
2 | N05W68 | 0010 | BXO |
 |
spotless | ||||
| 13564 | 2024.01.28 | 3 | S13W83 | 0040 | CAO | there are no spots at that position | |||||
| 13567 | 2024.01.28 2024.01.30 |
6 | 3 | N17W49 | 0015 | AXX |
 |
 |
location: N20W40 |
||
| 13570 | 2024.01.30 2024.02.01 |
4 | 2 | S03W35 | 0013 | BXO |
 |
 |
location: S02W32 |
||
| 13572 | 2024.01.31 2024.02.01 |
2 | 4 | 1 | S12W61 | 0010 | BXO | CRO |
 |
 |
area: 0013 |
| 13571 | 2024.01.31 2024.02.01 |
5 | 8 | 4 | S17W17 | 0120 | HAX | CAO |
 |
 |
area: 0140 location: S17W16 |
| 13575 | 2024.01.31 2024.02.02 |
3 | 3 | 3 | S37W90 | 0250 | CKO | DKC |
 |
 |
beta-delta reversed polarities location: S37W84 area: 0280 |
| 13573 | 2024.02.01 2024.02.01 |
N21W75 |
 |
location: N21W72 |
|||||||
| 13574 | 2024.02.01 2024.02.01 |
3 | 10 | 6 | N17W08 | 0020 | CRO | CRO |
 |
 |
area: 0040 location: N17W05 reversed polarities |
| S9395 | 2024.02.01 | N26W58 | |||||||||
| 13577 | 2024.02.02 2024.02.05 |
4 | 11 | 6 | N25W07 | 0010 | BXO | CRO |
 |
 |
area: 0040 location: N24W03 |
| 13576 | 2024.02.03 2024.02.03 |
37 | 96 | 59 | S16E33 | 0670 | FKC | FKC |
 |
 |
beta-gamma-delta area: 0990 location: S15E29 |
| S9401 | 2024.02.04 | 6 | 2 | S20W02 | 0008 | BXO |
 |
 |
|||
| 13578 | 2024.02.04 2024.02.05 |
4 | 15 | 7 | S04E41 | 0030 | CRO | CRO |
 |
 |
area: 0035 reversed polarities |
| S9403 | 2024.02.04 | S07W22 | |||||||||
| S9404 | 2024.02.05 | 3 | 2 | S14W74 | 0080 | HAX |
 |
 |
|||
| S9405 | 2024.02.05 | N39E33 |
 |
||||||||
| S9406 | 2024.02.06 | N12E58 |
 |
||||||||
| S9407 | 2024.02.06 | 2 | S16W57 | 0003 | BXO |
 |
 |
||||
| S9408 | 2024.02.06 | 8 | 4 | S10E48 | 0040 | DRO |
 |
 |
|||
| S9409 | 2024.02.07 | 1 | 1 | S21E83 | 0150 | HSX |
 |
||||
| 13579 | 2024.02.07 | 1 | S14E60 | 0050 | HAX | not sure what SWPC has observed, there are no spots at or near that location | |||||
| Total spot count: | 64 | 177 | 100 | ||||||||
| Sunspot number: | 164 | 317 | 230 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 105 | 227 | 150 | (Sum of total spot count + classification weighting for each AR. Classification weighting: X=0, R=3, A/S=5, H/K=10) | |||||||
| Relative sunspot number (Wolf number): | 180 | 174 | 184 | ||||||||
| Month | Average solar flux | International sunspot number (WDC-SILSO) |
Smoothed sunspot number (4) | Average ap (3) |
|
|---|---|---|---|---|---|
| Measured | 1 AU | ||||
| 2014.02 | 170.3 (cycle peak) |
166.3 | 146.1 (SC24 peak) | 110.5 | 10.70 |
| 2014.04 | 143.9 | 144.8 | 112.5 | 116.4 (SC24 solar max) | 7.88 |
| 2017.09 | 91.3 | 92.3 | 43.6 | 18.2 (-1.3) | 18.22 (SC24 peak) |
| 2019.11 | 70.2 | 68.7 | 0.5 | 2.0 (-0.6) (Solar minimum using 365d smoothing: November 17, 2019) |
4.19 |
| 2019.12 | 70.8 | 68.6 | 1.6 | 1.8 (-0.2) (ISN 13 months smoothed solar minimum) |
3.22 |
| 2022.06 | 116.1 | 119.8 | 70.3 | 81.1 (+3.7) | 8.20 |
| 2022.07 | 125.4 | 129.5 | 91.4 | 86.7 (+5.6) | 9.51 |
| 2022.08 | 114.2 | 117.1 | 74.6 | 92.6 (+5.9) | 10.92 |
| 2022.09 | 135.1 | 136.5 | 96.0 | 96.5 (+3.9) | 12.18 |
| 2022.10 | 133.5 | 132.7 | 95.5 | 98.9 (+2.4) | 11.16 |
| 2022.11 | 123.4 | 120.7 | 80.5 | 101.2 (+2.3) | 9.33 |
| 2022.12 | 147.9 | 143.4 | 112.8 | 106.7 (+5.5) | 10.99 |
| 2023.01 | 182.4 | 176.6 | 144.4 | 113.3 (+6.6) | 8.73 |
| 2023.02 | 167.2 | 163.2 | 111.3 | 117.8 (+3.5) | 14.48 (current SC25 peak) |
| 2023.03 | 157.2 | 155.6 | 123.3 | 121.1 (+3.3) | 14.42 |
| 2023.04 | 145.4 | 146.4 | 97.6 | 122.9 (+1.8) | 13.40 |
| 2023.05 | 155.6 | 159.2 | 137.4 | 124.1 (+1.2) | 10.67 |
| 2023.06 | 161.7 | 166.8 | 160.5 | 125.2 (+1.1) (SC25 solar max candidate) |
8.95 |
| 2023.07 | 176.4 | 182.2 | 160.0 | 124.3 (-0.9) | 8.15 |
| 2023.08 | 153.7 | 157.6 | 114.8 | (123.4 projected, -0.9) | 7.19 |
| 2023.09 | 154.4 | 156.0 | 134.2 | (123.1 projected, -0.3) | 14.26 |
| 2023.10 | 142.8 | 141.9 | 99.4 | (123.9 projected, +0.8) | 8.16 |
| 2023.11 | 153.5 | 150.2 | 105.4 | (123.9 projected, +0.0) | 12.20 |
| 2023.12 | 151.1 | 146.4 | 114.2 | (120.5 projected, -3.4) | 9.60 |
| 2024.01 | 164.6 | 159.3 | 123.0 | (117.1 projected, -3.3) | 5.46 |
| 2024.02 | 163.9 (1) | 34.7 (2A) / 143.7 (2B) / 167.6 (2C) | (116.3 projected, -0.8) | (4.3) | |
| 2024.03 | (115.8 projected, -0.5) | ||||
| 2024.04 | (115.7 projected, -0.1) | ||||
| 2024.05 | (117.0 projected, +1.3) | ||||
| 2024.06 | (116.2 projected, -0.8) | ||||
| 2024.07 | (114.5 projected, -1.7) | ||||
1) Running average based on the daily 20:00 UTC observed solar flux value at 2800 MHz
and any corrections applied to that measurement.
2A) Current impact on the monthly sunspot number based on the Boulder (NOAA/SWPC) sunspot number (accumulated daily sunspots / month days).
2B) Boulder SN current month average to date.
2C) STAR SDO 1K Wolf number 30 day average.
3) Running average based on the quicklook and definitive Potsdam WDC ap indices. Values in red
are based on the definitive international
GFZ Potsdam WDC ap indices.
4) Source: WDC-SILSO, Royal Observatory
Of Belgium, Brussels
The relatively low solar activity during the last months of 2023 significantly increased the possibility that solar cycle 25 has already peaked. Whether the first peak in June 2023 will be the actual solar max will not be known for some time. Due to the relatively high solar activity early in 2023 it is unlikely there will be another solar max candidate, if at all, until at least May 2024. Both the northern and southern polar fields, as well as the averaged total field, have already reversed polarities.
--------------------------------------------------------------------------------------
This report has been prepared by Jan Alvestad. It is based on the analysis of data from whatever sources are available at the time the report is prepared. All time references are to Universal Time. Comments and suggestions are always welcome.
SDO images are courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.
